Joint utilizing wedge-shaped rectangular locking shafts

ABSTRACT

A lightweight locking joint between two annularly or cylindrically shaped members in which at least one interfitting tongue and groove joint between the respective members is held in mating relationship by at least one set of two wedge-shaped rectangular shafts inserted into a common rectangular channel between the members through tangential access holes thereto, the common channel being formed by the telescopic juxtaposition of a partial channel in each member, each locking shaft wedging against the other of its set after sequential insertion of the shafts in oppositely disposed relationship in the channel filling the channel with the wedged shafts to insure a tight joint.

United States Patent Inventor Robert L. Alvis Albuquerque, N. Mex.

Appl. No. 859,469

Filed Sept. 19, 1969 Patented Aug. 17, 1971 Assignee The United Statesof America as represented by the United States Atomic Energy CommissionJOINT UTILIZING WEDGE-SHAPED RECTANGULAR LOCKING SHAFTS 5 Claims, 5Drawing Figs.

U.S. Cl.'. 285/305,

Int. Cl F16] 37/00 Field of Search 285/305, 421, 403; 287/53 T, 53 KReferences Cited UNITED STATES PATENTS 1,692,798 11/1928 Potter 285/421X 3,181,897 5/1965 Krayenbuhlet a1 285/305 X FOREIGN PATENTS 1,310,71210/1962 France 285/305 Primary Examiner- Dave W. Arola Attorney-RolandA. Anderson ABSTRACT: A lightweight locking joint between two annularlyor cylindrically shaped members in which at least one interfittingtongue and groove joint between the respective members is held in matingrelationship by at least one set of two wedge-shaped rectangular shaftsinserted into a common rectangular channel between the members throughtangential access holes thereto, the common channel being formed by thetelescopic juxtaposition of a partial channel in each member, eachlocking shaft wedging against the other of its set after sequentialinsertion ofthe shafts in oppositely disposed relationship in thechannel filling the channel with the wedged shafts to insure'a tightjoint.

, PATENTEDAUBIYIHYI 3600.011

IN VEN TOR ROBERT L. ALVIS 63 so'4o J so as so JOINT UTILIZINGWEDGE-SHAPED RECTANGULAR LOCKING SHAFTS I BACKGROUND OF INVENTIONJoining two members together often presents special problems when thejoint must be lightweight and must be required to be fastened quickly,reliably and easily. Additional problems are presented if the joint isto be made between two hollow members such .as hollow cylinders whereinno access is available to .the inside of the members during thefastening, or, conversely whereno access is available to the outside ofthe members, or where no access is available to some singular portionsof the inside of the members where the joint is to be made.

One type joint which has been proposed for joining two hollowcylindrical segments forms the respective segment ends so that one has aportion which surrounds and telescopically receives the other. Annulargrooves are cut in overlapping surfaces of the telescopically mountedsegments which together form a common groove. A plurality of accessholes are provided to the common groove, and a plurality of singlelocking elements are inserted through the access holes into the commongroove. .The locking elements are positioned within the common groove insuch a manner that the cylindrical segments are locked together.

The use of a single locking element in this type joint has severaldisadvantages. Since the diameter of the common groove is the same allthe way around, and the locking element is of the same width all alongits length, in order to achieve a snug fit over the relatively longlength of the locking element, considerable insertion force must beapplied, often requiring the use of a pneumatic hammer. It is likewisedifficult to remove a locking element once inserted from its lockedposition.

BRIEF DESCRIPTION OF THE DRAWING The invention is illustrated in theaccompanying drawing wherein:

FIG. 1 is a partially cut away plan view of a preferred embodiment ofthe joint of the invention;

FIG. 2 is a cross-sectional view of the embodiment illustrated in FIG. 1taken along lines 2-2 in FIG. 1;

FIG. 3 is a perspective view of the wedge-shaped rectangular lockingshafts used in the practice of the invention, illustrating theirinterrelationship; I

FIG. 4 is a partially cutaway plan view of a second preferred embodimentof the joint of the'invention; and

FIG. 5 is a cross sectional view of the embodiment illustrated in FIG. 4taken along lines 5-5 in FIG. 4.

In the drawing, the dimensions and shapes have been exaggerated forclarity and ease of description. Like reference numbers in therespective FIGS-of the drawing denote like parts.

BRIEF DESCRIPTION OF THE INVENTION In light of the foregoing, it is,therefore, an object of the invention to provide a tight, lightweightjoint which can be achieved quickly, reliably and easily, and into whichcan be incorporated a hermetic or other type seal.

This and other objects, features and advantages will be apparent tothose skilled inthe art from the following description, attached claims,and appended drawing.

The joint of the invention includes a first member having an end with afirst groove cut in an inside face thereof. Extending through the end ofthe member to the first groove is a hole or a plurality of holes cutapproximately tangentially to the groove. A second member having an endwith a second groove cut in an outside face thereof is telescopicallymated within the end of the first member with the first and secondgrooves juxtaposed -to form a common channel between the first andsecond members. To lock the first and second members together at leastone set of two shafts is used, each shaft being of substantiallyrectangular cross section and being formed along its length into a wedgewith its widest end of width less than the width of but more thanone-half of the width of the common channel. Each set of two shafts isinserted together into the common groove through the holes in the firstmember with the widest ends of the shafts of each set disposed inopposite directions. Thus, the combination of each set of shaftscompletely fills the common channel and are locked therein by thewedging action between them.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodimentof the joint of the invention between member 11 and member 12 is denotedby the numeral 10 in FIGS. 1 and 2. Member 11 and member 12 may be ofalmost any shape, such as rectangular, oval, or round; members 11 and 12are illustrated and described herein as cylinders since in practicecylindrical shaped members would be the most likely encountered.

End wall portions 13 and 14 of respective members 11 and 12 are formedto allow member 12 to be telescopically inserted within member 11, and,to aid in stability and security or tightness of the joint, wallportions 13 and 14 have tongues 15 and 16, respectively, formed thereonto fit into mating grooves 17 and 18, respectively, on end wall portionof the other member. The tongues and grooves are not essential to theinvention, but may be desirable if the joint and members are subjectedto stress environments.

To effect a seal between the inside 19 and outside 20 of the cylinders,a gasket 21 is provided within groove 18 upon which tongue 16 exertspressure. Gasket 21 may be of any sealing material, such as neoprene,rubber, or the like.

As illustrated, a groove 22 is formed on the outside and completelyaround the wall portion 14 of member 12. A similar groove 23 is formedon the inside and completely around the wall portion 13 of member 11.With the members 11 and 12 in telescopically mating relationship,grooves 22 and 23 are juxtaposed to form a common channel, denotedhereinafter by the reference numerals 22-23, between the wall portions13 and 14 of the members. Access to the common channel 22-23 is achievedby holes 24 (FIG. 2), the holes being formed through wall 13substantially along a line tangential to the wall portion 14 of member12.

To lock the members lland 12 together, a plurality of sets of twoshafts, one set of which being illustrated in FIG. 3, are inserted intocommon channel 22-23. As illustrated in FIG. 3, each shaft 30 and 30' isidentical to the other, having a rectangular cross section and a wedgecut extending along its length. Although the amount of taper of thewedge is not critical, the end 31 should be less than the width of thecommon channel 22-23, but should be just slightly greater than one-halfthe width of the common channel 22-23. Since the shafts 30 and 30' mustassume an arcuate configuration within common channel 22-23 in the caseof joining cylindrical members, slots or kerfings 32 and 32' may be cuton the underside of the shafts 30 and 30'. Additionally, to easeinsertion and prevent binding of the shafts, the outside edges may betrimmed to eliminate any sharp, binding edges, or perhaps even formedinto a semicircular shape, and, also, the shafts may be coated with alubricating substance (not shown) such as graphite, silicone, or thelike.

As illustrated particularly in FIG. 2, shaft 30' is first inserted intocommon channel 22-23 with the widest end of the wedge first.Subsequently, the second shaft 30 of the set is inserted, smallest endfirst, into common cavity 22-23 and wedged into position next to shaft30'. Ideally, the lengths of shafts 30 and 30' and the degree of wedgethereof should be such that the shafts are allowed to extend from onehole 24 around to the next, yet remain partially within hole 24 for easeof removal. Thus, the reason for the requirement tat the widest end 31be larger than one-half of the width of common channel 22-23 can beseen: in order to present substantially even pressure along the lengthof common channel 22-23, since the shafts 30 and 30' should ultimatelybe disposed substantially entirely side by side, the sum of the widthsall along the shafts should just equal, and perhaps just exceed for atight joint, the width of common channel 22-23. It can be seen, ofcourse, that because the shafts are of a wedge shape, the joint can bemade as tight as desired by merely applying an inserting pressure toshaft 30 to drive it outwardly from shaft 30 along its length. Also,because of the surface friction between the two shafts all along thejuxtaposed wedge faces, the shafts are not easily removable withoutexerting a removal force directly upon them, and a failure of the jointcan occur only if the shafts are sheared all along their lengths.

A second preferred embodiment of the invention is illustrated in FIGS. 4and 5. In the illustrated embodiment a first member 50 is joined to theinside ofa second member 51 by the joint of the invention 52, as may beencountered, for example, in partitioning a cylindrical (or othershaped) member. To achieve the joint, a wall portion 53 is formed onmember 50, and a mating surface 54 is formed on the inside wall ofmember 51. Again, if desired for stability, a tongue and groove, such astongue 55 on wall portion 53 and groove 56 on mating surface 54, may beutilized. A sealing gasket 57 may also be disposed within groove 56 toseal area 58 from area 59 on the other side of partitioning member 50and area 60 outside member 51.

A groove 61 is cut in and around the outside of wall portion 53 ofmember 50, and a corresponding groove 62 is cut in and around matingsurface 54 of member 51 to form a common channel 61-62.

Although access holes to common channel 61-62 may be cut through themating surface 54, from area 60, similar to those described in thepreferred embodiment illustrated in FIGS. I and 2, the access holes mayalso be cut through both mating surface 54 and wall portion 53, fromarea 59, as illustrated particularly in FIG. 5. Thus, the locking shafts30 and 30 will necessarily be inserted through holes 63 one on top ofthe other rather than side by side, as above described with reference toFIGS. 1 and 2. The same criterion for the locking sets apply to thelength, widths, and degree of wedge, as above described with respect toFIGS. 1 and 2.

Although the invention has been described and illustrated with a certaindegree of particularlity, itjs understood that the present disclosure ismade by way of example only and that various changes, modifications, andarrangements will occur to one skilled in the art without departing fromthe spirit and scope of the invention.

What I claim is:

1. A joint structure comprising, a first tubular member having a wallwith a first groove cut in an inside face thereof and at least one holeextending through said wall and communicating with said groove, a secondtubular member having a wall with a second groove cut in an outside facethereof, the wall of said second member being telescopically matedwithin the wall of said first member with said first and second groovesjuxtaposed to form a common annular channel of generally uniform widthand height between said members, at least one set of two elongatedflexible shafts, each shaft being of wedge shape along its length, thewidth of each shaft at the widest point of said wedge being less thanthe width of said common channel but more than one-half of the width ofsaid common channel for ready movement of a shaft through the channel,said set of two shafts being insertable into said common groove throughthe at least one hole in said first member by sliding a first shaft wideend first into said groove followed by a second shaft oppositelydisposed with respect to the first shaft, the widest end of said firstshaft being disposed remote from said one hole and the widest end ofsaid second shaft being disposed adjacent said one hole and within theouter circumference of said first tubular member and the combination ofsaid set of shafts completely filling the common channel width only whensaid second shaft wedges against said first shaft as the combined shaftwidths reach said groove width and locked in said common channel by saidwedging action and frictional forces between the wedged juxtaposedlength of said shafts to lock said first and second members together.

.2. The joint of claim 1 wherein said at least one hole extends from anoutside face of said first member through said wall into said commongroove.

3. The joint of claim I wherein said at least one hole extends throughan interior wall portion of said first tubular member adjoining andcommunicating with at least one hole of said second member to form acommon access hole between said first and second members to said commongroove.

4. The joint of claim 1 further comprising at least one mateable tongueand groove on the respective walls of said first and second members.

5. The joint of claim 4 further comprising a sealing member disposedwithin the groove of said tongue and groove.

1. A joint structure comprising, a first tubular member having a wallwith a first groove cut in an inside face thereof and at least one holeextending through said wall and communicating with said gRoove, a secondtubular member having a wall with a second groove cut in an outside facethereof, the wall of said second member being telescopically matedwithin the wall of said first member with said first and second groovesjuxtaposed to form a common annular channel of generally uniform widthand height between said members, at least one set of two elongatedflexible shafts, each shaft being of wedge shape along its length, thewidth of each shaft at the widest point of said wedge being less thanthe width of said common channel but more than one-half of the width ofsaid common channel for ready movement of a shaft through the channel,said set of two shafts being insertable into said common groove throughthe at least one hole in said first member by sliding a first shaft wideend first into said groove followed by a second shaft oppositelydisposed with respect to the first shaft, the widest end of said firstshaft being disposed remote from said one hole and the widest end ofsaid second shaft being disposed adjacent said one hole and within theouter circumference of said first tubular member and the combination ofsaid set of shafts completely filling the common channel width only whensaid second shaft wedges against said first shaft as the combined shaftwidths reach said groove width and locked in said common channel by saidwedging action and frictional forces between the wedged juxtaposedlength of said shafts to lock said first and second members together. 2.The joint of claim 1 wherein said at least one hole extends from anoutside face of said first member through said wall into said commongroove.
 3. The joint of claim 1 wherein said at least one hole extendsthrough an interior wall portion of said first tubular member adjoiningand communicating with at least one hole of said second member to form acommon access hole between said first and second members to said commongroove.
 4. The joint of claim 1 further comprising at least one mateabletongue and groove on the respective walls of said first and secondmembers.
 5. The joint of claim 4 further comprising a sealing memberdisposed within the groove of said tongue and groove.